A semiconductor light emitting element having a conductive substrate attached to a semiconductor layered body as disclosed in Patent Document 1 (Japanese Patent Laying-Open No. 09-008403) is expected as an effective approach for achieving high-intensity light emission as a light emitting diode. In particular, a semiconductor light emitting element using nitride semiconductor is attracting attention as a material expected to provide light emission in a wide light wavelength band.
FIG. 12 is a schematic cross sectional view of an exemplary conventional semiconductor light emitting element having a conductive substrate attached to a semiconductor layered body.
The conventional semiconductor light emitting element has a structure in which, on a conductive substrate 102 having a first ohmic electrode layer 101 and a second ohmic electrode layer 103 formed on respective sides thereof, the following layers are stacked sequentially: a first bonding metal layer 104a; a second bonding metal layer 104b; a barrier layer 105; a reflective layer 106; a p-side ohmic electrode layer 107; a p-type semiconductor layer 108; a light emitting layer 109; an n-type semiconductor layer 110; and an n-side ohmic electrode layer 111.
The semiconductor light emitting element having such a structure is fabricated, for example, as described below. Firstly, the second ohmic electrode layer 103 and the first bonding metal layer 104a are stacked in this order on conductive substrate 102 to fabricate a first wafer. In addition, n-type semiconductor layer 110, light emitting layer 109, and p-type semiconductor layer 108 are sequentially grown on a growth substrate, and thereafter p-side ohmic electrode layer 107, reflective layer 106, barrier layer 105, and the second bonding metal layer 104b are stacked in this order to fabricate a second wafer.
Next, the first bonding metal layer 104a of the first wafer and the second bonding metal layer 104b of the second wafer are bonded to fabricate a wafer bonded body. Subsequently, the growth substrate is removed from the second wafer of the wafer bonded body. Then, the first ohmic electrode layer 101 is formed on a rear surface of conductive substrate 102, and n-side ohmic electrode layer 111 is formed on a surface of n-type semiconductor layer 110.
Thereafter, the wafer bonded body having the first ohmic electrode layer 101 and n-side ohmic electrode layer 111 formed thereon is cut into chips, and thereby the conventional semiconductor light emitting element having the structure shown in FIG. 12 is obtained.